FINGER GRIP FOR SHEARS

Abstract

A shears upper finger grip has a lower substantially flat inner surface arranged in a transverse plane substantially normal to a cutting plane and dimensioned and configured to enable substantially full insertion of a thumb metacarpal bone from a right lateral side and for receiving the ball of the thumb to enable the thumb to be moved to a position on a left lateral side to an orientation substantially parallel to the cutting plane and to position the hand's thenar eminence into abutment against the flat inner surface while positioning at least exterior right lateral portions of the upper finger grip in abutment against the palm beyond the hand's thenar crease and into the region of at least one of the hand's palmar creases to enable the thenar eminence and palm of the hand to oppose the forces applied by the fingers acting on the lower finger grip.

Claims

1. (canceled)

2. The pair of shears as defined in claim 9, wherein said first one of the finger grips is formed with a leading curved surface that is a continuation of said substantially flat inner surface on said left lateral side to accommodate the skin web between the thumb and the index finger, or the thenar web space, when the thumb is substantially aligned with said blades.

3. The pair of shears as defined in claim 9, wherein said first finger grip is formed as an annular loop that defines a central axis that diverges from said cutting plane at an angle within the range of 50° to 60°.

4. The pair of shears as defined in claim 3, wherein said angle is equal to approximately 55°.

5. (canceled)

6. The pair of shears as defined in claim 9, wherein said range is 15°-17°.

7. The pair of shears as defined in claim 9, wherein substantial portions of said first and second finger grips are positioned on opposite sides of said axis.

8. The gripping structure as defined in claim 1, wherein said first and second finger grips are positioned above said axis.

9. A pair of shears comprising two levers pivotably connected at a pivot point and having distal ends that define substantially parallel blades, said blades defining a medial cutting plane and a first lateral side of said cutting plane through which a user's fingers are initially inserted and an opposing second lateral side on the other side of said medial cutting plane and said blades being pivotably movable about said pivot point between open and closed positions within said cutting plane and, in said closed position, said blades define a line or longitudinal axis with said pivot point, said levers being formed at a proximal end relative to said pivot point with a pair of finger grips, a first one of the finger grips being a superior finger grip for receiving a user's thumb having a portion most proximate to said axis formed with a substantially flat inner surface, said substantially flat surface being inclined from said second lateral side to said first lateral side at an angle within a range of 10°-20° relative to a plane transverse to said cutting plane that is coextensive with a surface of said first one of said finger grips facing or is in opposition to said second one of said finger grips, said first one of the finger grips being dimensioned and configured to enable a user's thumb to be inserted through said first one of said finger grips from said first lateral side to said second lateral side to enable the thumb to be moved to a position on said second lateral side to an orientation substantially parallel to said cutting plane and to position the hand's thenar eminence into abutment against said substantially flat inner surface of said first one of the finger grips, and a second one of the finger grips being configured and dimensioned to be gripped by at least one of the other four fingers of the hand, whereby said first one of the finger grips enables a thenar eminence and palm of the hand of a user to oppose forces applied by the fingers acting on said second one of the finger grips.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other aspects, features and advantages of the present invention will be more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

[0017] FIG. 1 is a left perspective view of a scissors or shears in accordance with the invention, shown in a fully closed condition;

[0018] FIG. 2 is a left lateral side view of the scissors or shears shown in FIG. 1, showing in phantom outline the positions of the fingers of the hand during normal use;

[0019] FIG. 3 is similar to FIG. 2 when the scissors or shears are in a partially open condition;

[0020] FIG. 4 is a top plan view of the scissors or shears shown in FIGS. 1-3;

[0021] FIG. 5 is a bottom plan view of the scissors or shears shown in FIGS. 1-4, showing in phantom outline the position of the hand during initial insertion of the thumb and prior to gripping of the handles;

[0022] FIG. 6 is an enlarged fragmented view, as viewed from the right lateral side to show details of the configuration of the upper finger grip;

[0023] FIG. 7 is a cross-sectional view of the upper finger grip shown in FIG. 6, taken along line 7-7;

[0024] FIG. 8 is a bottom plan view of the scissors or shears shown in the previous Figures, broken away to illustrate the lower configuration of the upper finger grip and the manner that it is arranged in relation to the thenar eminence and the palmer surfaces of the hand;

[0025] FIG. 9 is similar to FIG. 2 and shows another embodiment of a shears in which both finger grips are angularly offset from the axis to position both grips above the axis;

[0026] FIG. 10 is similar to FIGS. 2 and 9 and shows still a further embodiment of a shears in which both finger grips are linearly offset from the axis to position both grips above the axis; and

[0027] FIG. 11 is a cross-sectional view of the finger grips shown in FIG. 2 taken along line 11-11.

DETAILED DESCRIPTION

[0028] Referring now specifically to the Figures, in which identical or similar parts are designated by the same reference numerals throughout, and first referring to FIG. 1, a scissors, shears, snips or other like cutting instrument is generally designated by the reference 10. All such cutting tools will be collectively referred to herein as “shears”.

[0029] The shears 10 includes two levers 12, 14 connected to each other at a pivot 16 forming a pivot point. The levers form substantially parallel blades 12a, 14a. The blades 12, 14 define a medial cutting plane CP and are pivotably movable about the pivot 16 between open and closed positions within the cutting plane. In a closed position, the blades 12, 14 define a line or longitudinal axis A with the pivot 16.

[0030] Each lever is formed at a proximal end relative to the pivot 16 with a finger grip. A first finger grip 12b is a superior or an upper finger grip formed above the line or axis A. The first or upper finger grip is formed above the line or axis A and has a lower portion 12c formed with a substantially flat inner surface 12d closest to and extending longitudinally along a direction generally parallel to the line or axis A when the blades are closed.

[0031] The first or upper finger grip 12b is dimensioned and configured to enable substantially full insertion of a thumb metacarpal bone from a right lateral side through the upper finger grip 12b for receiving the ball of the thumb or thenar eminence (TE), as best shown in FIGS. 5 and 8 from a right lateral side through the finger grip 12(b) and for receiving the ball of the thumb to enable the thumb to be moved to a position on the left lateral side to an orientation substantially parallel to the cutting plane CP and to position the hands' thenar eminence TE into abutment against the generally flat inner surface 12d of the upper finger grip 12b while positioning at least the exterior right lateral portion 12e of the finger grip into abutment or contact with the palm P of the hand, as best shown in FIG. 8 beyond the hand's thenar crease TC and into the region of at least one of the hand's palmar creases PC1 and PC2.

[0032] The second or lower finger grip 14b, in the embodiment shown in FIGS. 1-8, is arranged below the line or axis A and is configured and dimensioned to be gripped by the other four fingers or at least some of the other four fingers of the hand as shown in FIGS. 2 and 3. However, the positions of the finger grips relative to the axis A is not critical and can be angularly or linearly offset from the axis. See, for example, FIG. 9 in which both finger grips are angularly offset from the axis to position both finger grips above the axis, and FIG. 10 in which both finger grips are linearly offset from the axis to again position both finger grips above the axis. The offsets can also position the finger grips below the axis and can result from offsets opposite from the ones shown in FIGS. 9 and 10, and can also include combinations of linear and angular offsets.

[0033] The first or upper finger grip 12b is configured as an annular loop preferably formed with a recessed curved surface 12f the at the leading or distal end that is a continuation of the flat inner surface 12d, on the left lateral side, to accommodate the thenar web space or skin web between the thumb and the index finger, when the thumb is substantially aligned with the blades 12a, 14a.

[0034] Referring to FIG. 4, the upper finger grip 12b defines a central axis A′ that diverges or is angularly offset from the cutting plane CP or the axis A at an angle θ that is within the range of 50°-60°. Preferably, the angle θ is equal to approximately 55°.

[0035] The inner surface 12d is substantially flat, as shown in FIG. 11, to distribute the forces uniformly across the thenar eminence or the ball of the thumb and the thenar muscles. Without having any meaningful curvature or peaks in this surface 12d force concentrations on the thenar muscles are avoided, preventing potentially significant pain to the user. Also, in order to render the tool more ergonomic and comfortable to use the flat surface 12d may be somewhat inclined upwardly from the right lateral side towards the left lateral side to conform to the shape of the hand while in gripping engagement with the upper finger grip 12b. The inclination of the flat surface is best shown in FIG. 11 where the surface is shown inclined downwardly from the left to the right side relative to a plane NP substantially normal to the cutting plane CP. The inclination angle γ is within the range of 10°-20° and, preferably within the range 15°-17°.

[0036] In preparation for use of the shears, referring to FIG. 5, the thumb is fully inserted into the upper finger grip 12b so that the thenar eminence TE rests upon the substantially flat surface 12d and the thumb can be moved to the position shown in FIG. 8 where the thumb is substantially aligned with the blades 12a, 14a. Once the fingers are flexed to gripping positions, the right exterior lateral portion or edge 12e is placed into abutment with the palmer surface PS, beyond the thenar crease TC and into contact with the palmar creases PC1 and/or PC2. Importantly, the thumb, once in the position shown in FIG. 3, serves to primarily stabilize and guide the direction of cutting while eliminating or substantially reducing the flexing forces applied by the thumb in opposition or to counter the squeezing forces of the other four fingers that act on the lower finger grip 14b, those forces being absorbed or countered by the palm of the hand. Thus, the thenar muscles do not need to flex during operation of the shears but can remain substantially stationary, substantially reducing stress and strain on the thumb. The design is not only ergonomic but renders the shears more comfortable and easy to use while avoiding fatigue especially with prolonged use or while cutting heavier materials.

[0037] While the shears 10 shown in FIGS. 1-8 shows a shears in which the upper grip 12b is generally located above the axis A and the lower grip 14b is positioned below the axis the invention may be used with other configured shears, scissors or snips. Thus, referring to FIGS. 9 and 10 other common configurations of shears are illustrated in which both the upper and lower grips are positioned above the axis A. In all cases the configuration aforementioned for the upper grip 12b is substantially the same.

[0038] The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.